diff mbox series

[6/7] drm: atmel-hlcdc: enable sys_clk during initalization.

Message ID 1551284609-14594-7-git-send-email-claudiu.beznea@microchip.com (mailing list archive)
State New, archived
Headers show
Series add LCD support for SAM9X60 | expand

Commit Message

Claudiu Beznea Feb. 27, 2019, 4:24 p.m. UTC
From: Sandeep Sheriker Mallikarjun <sandeepsheriker.mallikarjun@microchip.com>

For SAM9X60 SoC, sys_clk is through lcd_gclk clock source and this
needs to be enabled before enabling lcd_clk.

Signed-off-by: Sandeep Sheriker Mallikarjun <sandeepsheriker.mallikarjun@microchip.com>
[claudiu.beznea@microchip.com: add fixed_clksrc checks]
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

Comments

Sam Ravnborg Feb. 28, 2019, 9:55 p.m. UTC | #1
Hi Claudiu

On Wed, Feb 27, 2019 at 04:24:40PM +0000, Claudiu.Beznea@microchip.com wrote:
> From: Sandeep Sheriker Mallikarjun <sandeepsheriker.mallikarjun@microchip.com>
> 
> For SAM9X60 SoC, sys_clk is through lcd_gclk clock source and this
> needs to be enabled before enabling lcd_clk.

We have "ownership" of the clocks in the mfd device.
So it would make more sense to let the mfd device handle
the base clocks.
In other words - what about pushing enable of perigh_clk and sys_clk to
the mfd driver.

This may have the nice side-effect that we avoid
that both the drm driver and the pwm driver enable/disable the periph_clk
as it is today.

Another comment - fixed_clksrc is used to determine if sys_clk is enabled.
But that flag is about the clksource selection, and it is just a coincidence
that the same flag can be used here.
Why we cannot always enable sys_clk? Do we need to do this only
for sam9x60?
IF yes, then add a new falg. If no, then skip the flag.

	Sam


> 
> Signed-off-by: Sandeep Sheriker Mallikarjun <sandeepsheriker.mallikarjun@microchip.com>
> [claudiu.beznea@microchip.com: add fixed_clksrc checks]
> Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
> ---
>  drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c | 19 ++++++++++++++++++-
>  1 file changed, 18 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
> index 0be13eceedba..8bf51f853721 100644
> --- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
> +++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
> @@ -625,10 +625,18 @@ static int atmel_hlcdc_dc_load(struct drm_device *dev)
>  	dc->hlcdc = dev_get_drvdata(dev->dev->parent);
>  	dev->dev_private = dc;
>  
> +	if (dc->desc->fixed_clksrc) {
> +		ret = clk_prepare_enable(dc->hlcdc->sys_clk);
> +		if (ret) {
> +			dev_err(dev->dev, "failed to enable sys_clk\n");
> +			goto err_destroy_wq;
> +		}
> +	}
> +
>  	ret = clk_prepare_enable(dc->hlcdc->periph_clk);
>  	if (ret) {
>  		dev_err(dev->dev, "failed to enable periph_clk\n");
> -		goto err_destroy_wq;
> +		goto err_sys_clk_disable;
>  	}
>  
>  	pm_runtime_enable(dev->dev);
> @@ -664,6 +672,9 @@ static int atmel_hlcdc_dc_load(struct drm_device *dev)
>  err_periph_clk_disable:
>  	pm_runtime_disable(dev->dev);
>  	clk_disable_unprepare(dc->hlcdc->periph_clk);
> +err_sys_clk_disable:
> +	if (dc->desc->fixed_clksrc)
> +		clk_disable_unprepare(dc->hlcdc->sys_clk);
>  
>  err_destroy_wq:
>  	destroy_workqueue(dc->wq);
> @@ -688,6 +699,8 @@ static void atmel_hlcdc_dc_unload(struct drm_device *dev)
>  
>  	pm_runtime_disable(dev->dev);
>  	clk_disable_unprepare(dc->hlcdc->periph_clk);
> +	if (dc->desc->fixed_clksrc)
> +		clk_disable_unprepare(dc->hlcdc->sys_clk);
>  	destroy_workqueue(dc->wq);
>  }
>  
> @@ -805,6 +818,8 @@ static int atmel_hlcdc_dc_drm_suspend(struct device *dev)
>  	regmap_read(regmap, ATMEL_HLCDC_IMR, &dc->suspend.imr);
>  	regmap_write(regmap, ATMEL_HLCDC_IDR, dc->suspend.imr);
>  	clk_disable_unprepare(dc->hlcdc->periph_clk);
> +	if (dc->desc->fixed_clksrc)
> +		clk_disable_unprepare(dc->hlcdc->sys_clk);
>  
>  	return 0;
>  }
> @@ -814,6 +829,8 @@ static int atmel_hlcdc_dc_drm_resume(struct device *dev)
>  	struct drm_device *drm_dev = dev_get_drvdata(dev);
>  	struct atmel_hlcdc_dc *dc = drm_dev->dev_private;
>  
> +	if (dc->desc->fixed_clksrc)
> +		clk_prepare_enable(dc->hlcdc->sys_clk);
>  	clk_prepare_enable(dc->hlcdc->periph_clk);
>  	regmap_write(dc->hlcdc->regmap, ATMEL_HLCDC_IER, dc->suspend.imr);
>  
> -- 
> 2.7.4
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
Claudiu Beznea March 1, 2019, 10:07 a.m. UTC | #2
On 28.02.2019 23:55, Sam Ravnborg wrote:
> Hi Claudiu
> 
> On Wed, Feb 27, 2019 at 04:24:40PM +0000, Claudiu.Beznea@microchip.com wrote:
>> From: Sandeep Sheriker Mallikarjun <sandeepsheriker.mallikarjun@microchip.com>
>>
>> For SAM9X60 SoC, sys_clk is through lcd_gclk clock source and this
>> needs to be enabled before enabling lcd_clk.
> 
> We have "ownership" of the clocks in the mfd device.
> So it would make more sense to let the mfd device handle
> the base clocks.
> In other words - what about pushing enable of perigh_clk and sys_clk to
> the mfd driver.

I think this could be achieved, but how is better? To have individual
drivers (in this care I would say, child drivers, like e.g. this lcd
driver) taking decisions on their own for their resources (even if shared)
or to have parents taking decisions for them? Just asking.

> 
> This may have the nice side-effect that we avoid
> that both the drm driver and the pwm driver enable/disable the periph_clk
> as it is today.
> 
> Another comment - fixed_clksrc is used to determine if sys_clk is enabled.
> But that flag is about the clksource selection, and it is just a coincidence
> that the same flag can be used here.

Yes, agree on this, I took advantage of fixed_clksrc to also enable the
sys_clk based on fixed_clksrc to avoid introducing another member in struct
atmel_hlcdc_dc_desc. At this moment this is valid only for SAM9X60 and I
was thinking that in case some other scenario will appear I will do the
appropriate changes.

> Why we cannot always enable sys_clk? Do we need to do this only
> for sam9x60?

Only SAM9X60 requires this explicitly at probe.

> IF yes, then add a new falg. If no, then skip the flag.
> 
> 	Sam
> 
> 
>>
>> Signed-off-by: Sandeep Sheriker Mallikarjun <sandeepsheriker.mallikarjun@microchip.com>
>> [claudiu.beznea@microchip.com: add fixed_clksrc checks]
>> Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
>> ---
>>  drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c | 19 ++++++++++++++++++-
>>  1 file changed, 18 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
>> index 0be13eceedba..8bf51f853721 100644
>> --- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
>> +++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
>> @@ -625,10 +625,18 @@ static int atmel_hlcdc_dc_load(struct drm_device *dev)
>>  	dc->hlcdc = dev_get_drvdata(dev->dev->parent);
>>  	dev->dev_private = dc;
>>  
>> +	if (dc->desc->fixed_clksrc) {
>> +		ret = clk_prepare_enable(dc->hlcdc->sys_clk);
>> +		if (ret) {
>> +			dev_err(dev->dev, "failed to enable sys_clk\n");
>> +			goto err_destroy_wq;
>> +		}
>> +	}
>> +
>>  	ret = clk_prepare_enable(dc->hlcdc->periph_clk);
>>  	if (ret) {
>>  		dev_err(dev->dev, "failed to enable periph_clk\n");
>> -		goto err_destroy_wq;
>> +		goto err_sys_clk_disable;
>>  	}
>>  
>>  	pm_runtime_enable(dev->dev);
>> @@ -664,6 +672,9 @@ static int atmel_hlcdc_dc_load(struct drm_device *dev)
>>  err_periph_clk_disable:
>>  	pm_runtime_disable(dev->dev);
>>  	clk_disable_unprepare(dc->hlcdc->periph_clk);
>> +err_sys_clk_disable:
>> +	if (dc->desc->fixed_clksrc)
>> +		clk_disable_unprepare(dc->hlcdc->sys_clk);
>>  
>>  err_destroy_wq:
>>  	destroy_workqueue(dc->wq);
>> @@ -688,6 +699,8 @@ static void atmel_hlcdc_dc_unload(struct drm_device *dev)
>>  
>>  	pm_runtime_disable(dev->dev);
>>  	clk_disable_unprepare(dc->hlcdc->periph_clk);
>> +	if (dc->desc->fixed_clksrc)
>> +		clk_disable_unprepare(dc->hlcdc->sys_clk);
>>  	destroy_workqueue(dc->wq);
>>  }
>>  
>> @@ -805,6 +818,8 @@ static int atmel_hlcdc_dc_drm_suspend(struct device *dev)
>>  	regmap_read(regmap, ATMEL_HLCDC_IMR, &dc->suspend.imr);
>>  	regmap_write(regmap, ATMEL_HLCDC_IDR, dc->suspend.imr);
>>  	clk_disable_unprepare(dc->hlcdc->periph_clk);
>> +	if (dc->desc->fixed_clksrc)
>> +		clk_disable_unprepare(dc->hlcdc->sys_clk);
>>  
>>  	return 0;
>>  }
>> @@ -814,6 +829,8 @@ static int atmel_hlcdc_dc_drm_resume(struct device *dev)
>>  	struct drm_device *drm_dev = dev_get_drvdata(dev);
>>  	struct atmel_hlcdc_dc *dc = drm_dev->dev_private;
>>  
>> +	if (dc->desc->fixed_clksrc)
>> +		clk_prepare_enable(dc->hlcdc->sys_clk);
>>  	clk_prepare_enable(dc->hlcdc->periph_clk);
>>  	regmap_write(dc->hlcdc->regmap, ATMEL_HLCDC_IER, dc->suspend.imr);
>>  
>> -- 
>> 2.7.4
>>
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel@lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
>
diff mbox series

Patch

diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
index 0be13eceedba..8bf51f853721 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
@@ -625,10 +625,18 @@  static int atmel_hlcdc_dc_load(struct drm_device *dev)
 	dc->hlcdc = dev_get_drvdata(dev->dev->parent);
 	dev->dev_private = dc;
 
+	if (dc->desc->fixed_clksrc) {
+		ret = clk_prepare_enable(dc->hlcdc->sys_clk);
+		if (ret) {
+			dev_err(dev->dev, "failed to enable sys_clk\n");
+			goto err_destroy_wq;
+		}
+	}
+
 	ret = clk_prepare_enable(dc->hlcdc->periph_clk);
 	if (ret) {
 		dev_err(dev->dev, "failed to enable periph_clk\n");
-		goto err_destroy_wq;
+		goto err_sys_clk_disable;
 	}
 
 	pm_runtime_enable(dev->dev);
@@ -664,6 +672,9 @@  static int atmel_hlcdc_dc_load(struct drm_device *dev)
 err_periph_clk_disable:
 	pm_runtime_disable(dev->dev);
 	clk_disable_unprepare(dc->hlcdc->periph_clk);
+err_sys_clk_disable:
+	if (dc->desc->fixed_clksrc)
+		clk_disable_unprepare(dc->hlcdc->sys_clk);
 
 err_destroy_wq:
 	destroy_workqueue(dc->wq);
@@ -688,6 +699,8 @@  static void atmel_hlcdc_dc_unload(struct drm_device *dev)
 
 	pm_runtime_disable(dev->dev);
 	clk_disable_unprepare(dc->hlcdc->periph_clk);
+	if (dc->desc->fixed_clksrc)
+		clk_disable_unprepare(dc->hlcdc->sys_clk);
 	destroy_workqueue(dc->wq);
 }
 
@@ -805,6 +818,8 @@  static int atmel_hlcdc_dc_drm_suspend(struct device *dev)
 	regmap_read(regmap, ATMEL_HLCDC_IMR, &dc->suspend.imr);
 	regmap_write(regmap, ATMEL_HLCDC_IDR, dc->suspend.imr);
 	clk_disable_unprepare(dc->hlcdc->periph_clk);
+	if (dc->desc->fixed_clksrc)
+		clk_disable_unprepare(dc->hlcdc->sys_clk);
 
 	return 0;
 }
@@ -814,6 +829,8 @@  static int atmel_hlcdc_dc_drm_resume(struct device *dev)
 	struct drm_device *drm_dev = dev_get_drvdata(dev);
 	struct atmel_hlcdc_dc *dc = drm_dev->dev_private;
 
+	if (dc->desc->fixed_clksrc)
+		clk_prepare_enable(dc->hlcdc->sys_clk);
 	clk_prepare_enable(dc->hlcdc->periph_clk);
 	regmap_write(dc->hlcdc->regmap, ATMEL_HLCDC_IER, dc->suspend.imr);